Search system, display unit, recording medium, apparatus, and processing method of the search system

ABSTRACT

Provided is a method comprising: maintaining forward network structure information that, with stages arranged in a multilayer structure and each stage including one or more nodes associated with one or more words and associated in whole or in part with a point, connects nodes included in different layers with each other, in order from a higher layer toward a lower layer in a network state; acquiring one or more search word to use for a search; acquiring a node including all or part of the acquired search words and converting the acquired search words into a point; and using the forward network structure information to calculate points by sequentially adding together in a manner to inherit points, in node units of each layer, the points associated with the acquired node along all paths connected by these points from a topmost layer to the node of a predetermined layer.

CROSS-REFERENCE TO RELATED APPLICATIONS

The contents of the following Japanese and PCT patent applications areincorporated herein by reference:

-   -   No. 2011-223306 filed in JP on Oct. 7, 2011    -   No. PCT/JP201.21006211 filed on Sep. 27, 2012

BACKGROUND

1. Technical Field

This invention relates to the search technology of a search system usinga database that has a forward network structure.

2. Related Art

Conventionally, for example, technology is known relating to a failurediagnosis apparatus for a vehicle, in which a cause and effectrelationship is set as a node and a technique is implemented forperforming a case search, for example, using a database having a forwardnetwork structure in which nodes are connected to each other in a treestructure, such as disclosed in Patent Document 1. With this technique,a so-called “inquiry type” search system is provided to determine thecause by tracing the connections between nodes in response to an inputanswer of a user to questions about the nodes, which are associated withthe tree.

As another example, although it is not a database having a forwardnetwork structure such as described above, a retrieval system isprovided that represents the elements to be searched by a plurality ofvectors and performs a search according to the matching degree withrespect to the vector of the search keywords, such as described inPatent Document 2.

-   Patent Document 1: Japanese Patent Laid-Open No. 62-004663 bulletin-   Patent Document 2: Japanese Patent Laid-Open No. 2005-011042    bulletin

However, the conventional technology mentioned above has the followingproblems. That is, with the technology of Patent Document 1, because itis necessary for a user to reply to questions one by one, thistechnology is not suitable for immediate decision making, since it takeseffort and time to get the desired answers.

In addition, in a case where the user can assume several possibleanswers to the question content or a case where the user cannot decideon a unique answer, the user must try all of the answers, or at worstfollow all of the diverging branches.

In addition, with the technique of Patent Document 2, search results canbe obtained instantly by appointing a plurality of search keywords, butthere is a problem because the linkage between the elements which areexpressed in a vector is judged based only on the distance and thedirection of each vector, and this is not suitable for the relation ofelements such as answers and results, for example, for the linkage ofelements such as “lighting of the HDD trouble lamp” and “trouble of theHDD”.

SUMMARY

According to a first aspect of the present invention, provided is asearch system comprising: a forward network structure informationmaintenance section that, with stages arranged in a multilayer structureand each stage including one or more nodes associated with one or morewords and associated in whole or in part with a point, maintains forwardnetwork structure information that connects nodes included in differentlayers with each other, in order from a higher layer toward a lowerlayer in a network state; a search word acquisition section acquiringone or more search words to use for a search; a node acquisition sectionhaving means to acquire a node including all or part of the acquiredsearch words and to convert the acquired search words into a point; apoint calculation section that, using the forward network structureinformation, calculates points by sequentially adding together in amanner to inherit points, in node units of each layer, the pointsassociated with the nodes acquired by the node acquisition section alongall of the paths connected by these points from a topmost layer to thenode of a predetermined layer; and a display control section thatcontrols display of the result obtained by ordering all or part of thenodes in the predetermined layer, using the points that have beencalculated for each node in the predetermined layer.

According to a second aspect of the present invention, provided is adisplay unit for displaying the results output by the search systemdescribed above.

According to a third aspect of the present invention, provided is acomputer-readable recording medium on which is recorded data having adata structure that contains a hierarchy of a plurality of nodes and aplurality of layers, wherein each of the one or more layers has at leastone or more nodes, the nodes are associated with one or more words andassociated in whole or in part with a point, and (i) a connection isformed from each of the at least one or more nodes included in any oneof the plurality of layers except the bottommost layer, toward at leastone or more nodes included in one or more layers at a lower positionthan the one layer, and each of the one or more nodes in the one layeris connected to neither the nodes in the one layer nor nodes in thehigher layers, or (ii) a connection is formed from each of the at leastone or more nodes included in any one of the plurality of layers exceptthe topmost layer, toward at least one or more nodes included in one ormore layers at a higher position than the one layer; and each of the oneor more nodes in the one layer is connected to neither the nodes in theone layer nor nodes in the lower layers.

According to a fourth aspect of the present invention, provided is anapparatus having a data structure that contains a hierarchy of aplurality of nodes and a plurality of layers, wherein each of the one ormore layers has at least one or more nodes, the nodes are associatedwith one or more words and associated in whole or in part with a point,and (i) a connection is formed from each of the at least one or morenodes included in any one of the plurality of layers except thebottommost layer, toward at least one or more nodes included in one ormore layers at a lower position than the one layer, and each of the oneor more nodes in the one layer is connected to neither the nodes in theone layer nor nodes in the higher layers, or (ii) a connection is formedfrom each of the at least one or more nodes included in any one of theplurality of layers except the topmost layer, toward at least one ormore nodes included in one or more layers at a higher position than theone layer, and each of the one or more nodes in the one layer isconnected to neither the nodes in the one layer nor nodes in the lowerlayers.

According to a fifth aspect of the present invention, provided is asearch system comprising: a means that displays a screen for acquiringone or more search words to use for a search; and a means that, uponreceiving input of a search word from a user, acquires points from aforward network structure information maintenance section that, withstages arranged in a multilayer structure and each stage including oneor more nodes associated with one or more words and associated in wholeor in part with a point, maintains forward network structure informationthat connects nodes included in different layers with each other, inorder from a higher layer toward a lower layer in a network state, wherethe points correspond to a node including all or part of the inputsearch words that are acquired, calculates points by sequentially addingtogether in a manner to inherit points, in node units of each layer, thepoints associated with the nodes along all of the paths connected bythese points from a topmost layer to the node of a predetermined layer,and displays a result of ordering all or part of the nodes of thepredetermined layer using the acquired points.

According to a sixth aspect of the present invention, provided is amethod comprising: maintaining forward network structure informationthat, with stages arranged in a multilayer structure and each stageincluding one or more nodes associated with one or more words andassociated in whole or in part with a point, connects nodes included indifferent layers with each other, in order from a higher layer toward alower layer in a network state; acquiring one or more search word to usefor a search; acquiring a node including all or part of the acquiredsearch words and converting the acquired search words into a point;using the forward network structure information to calculate points bysequentially adding together in a manner to inherit points, in nodeunits of each layer, the points associated with the acquired node alongall of the paths connected by these points from a topmost layer to thenode of a predetermined layer; and displaying the result obtained byordering all or part of the nodes in the predetermined layer, by usingthe points that have been calculated for each node in the predeterminedlayer.

According to a seventh aspect of the present invention, provided is asearch system including a forward network structure informationmaintenance section that, with stages (layers) arranged in a multilayerstructure and each stage including one or more nodes associated with oneor more words and associated in whole or in part with a point, maintainsforward network structure information that connects nodes included indifferent layers with each other, a search word acquisition sectionacquiring one or more search words to use for a search, a nodeacquisition section that acquires a node including all or part of theacquired search words, and a point calculation section that calculatesin a manner to inherit points, in units of the bottommost layer nodes,points associated with the nodes acquired by the node acquisitionsection from among nodes in the paths tracing connected nodes in theforward network structure.

In addition to the configuration described above, the search system mayinclude a result display section that displays the result obtained byordering all or part of the nodes in the bottommost layer, using thepoints that have been calculated for each node in the bottommost layer.Furthermore, the result display section may have a higher layer displaymeans to display as a list one or more words associated with nodes ofthe higher layers connected to each node of the bottommost layer.

In addition to the configuration described above, the point calculationsection may have a downward calculating means that performs thecalculating process by calculating the connected nodes from the topmostlayer towards the bottommost layer.

In addition to the configuration described above, among the nodesforming the tree structure, nodes of higher layers may be connected withnodes of lower layers by the one or more words in a manner to have acause and effect or effect and cause relationship.

In addition to the configuration described above, the forward networkstructure information maintenance section may include a pointmaintenance means, which maintains the points in association with thenodes, and a point modification means, which modifies the maintainedpoints.

In addition to the configuration described above, the search system mayhave a point modification control section to edit a value of pointsassociated with the node by use of all or part of the search wordsacquired by the search word acquisition section directly or indirectly.

In addition to the configuration described above, the search system maycalculate the points in units of a predetermined middle layer, insteadof units of the bottommost layer. Specifically, the search systeminclude a forward network structure information maintenance sectionthat, with stages arranged in a multilayer structure and each stageincluding one or more nodes associated with one or more words andassociated in whole or in part with a point, maintains forward networkstructure information that connects nodes included in different layerswith each other, a search word acquisition section acquiring one or moresearch words to use for a search, a node acquisition section thatacquires a node including all or part of the acquired search words, anda point calculation section that calculates in a manner to inheritpoints, in units of the predetermined middle layer nodes, pointsassociated with the nodes acquired by the node acquisition section fromamong nodes in the paths tracing connected nodes in the forward networkstructure.

In addition to the configuration described above, the search system mayinclude a result display section that displays the result obtained byordering all or part of the nodes in a layer lower than thepredetermined middle layer using the points that have been calculatedfor each node in the predetermined middle layer.

According to an eighth aspect of the present invention, provided is aprocessing method of the search system that includes a forward networkstructure information maintenance step that, with stages arranged in amultilayer structure and each stage including one or more nodesassociated with one or more words and associated in whole or in partwith a point, maintains forward network structure information thatconnects nodes included in different layers with each other, a searchword acquisition step acquiring one or more search words to use for asearch, a node acquisition step that acquires a node including all orpart of the acquired search words, a point calculation step thatcalculates in a manner to inherit points, in units of the bottommostlayer nodes, points associated with the nodes acquired by the nodeacquisition step from among nodes in the paths tracing connected nodesin the forward network structure.

In addition, the summary of the invention is not intended to list allnecessary features of the present invention, and the present inventionmay also be a sub-combination of the features described above.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 A conception diagram to explain an example of the search in thesearch system of embodiment 1

FIG. 2 A figure that shows an example of the function blocks in thesearch system of embodiment 1

FIG. 3A A figure that shows an example of forward network structureinformation maintained by the search system of embodiment 1

FIG. 3B A figure that expresses other examples of forward networkstructure information maintained by the search system of embodiment 1

FIG. 4 A figure that expresses an example of the GUI screen for thesearch word acquisition in the search system of embodiment 1

FIG. 5A A figure to explain the point calculation of the bottommostlayer nodes in the search system of embodiment 1

FIG. 5B Another figure to explain the point calculation of the bottomlayer nodes in the search system of embodiment 1

FIG. 6 A figure that shows an example of the display of the searchresults in the search system of embodiment 1

FIG. 7 A figure that shows an example of the hardware constitution inthe search system of embodiment 1

FIG. 8 A flow chart that shows an example of the flow of the processingin the search system embodiment 1

FIG. 9 A figure that shows an example of the function blocks in thesearch system of embodiment 2

FIG. 10 A flow chart that shows an example of the flow of the processingin the search system embodiment 2

FIG. 11A A figure that shows an example of the node contents editingscreen for editing the contents of the node

FIG. 11B A figure that shows an example of the link editing screen forediting the connection between the nodes

FIG. 12 A figure that shows an example of the function blocks in thesearch system of embodiment 3

FIG. 13 A figure that shows an example of the search system using thecloud

FORM TO CARRY OUT THE INVENTION

The following explains a form of the implementation of this inventionusing figures. In addition, the form of this implementation does notlimit the invention, and the invention can be embodied in various wayswithout deviating from the intent of the invention.

Embodiment 1

<Overview>

FIG. 1 is a conception diagram to explain an example of the search inthe search system of this embodiment. As shown in this figure, in thisexample, the nodes of the higher layer are associated with “effects” andthe nodes of the bottommost layer are associated with “causes,” tosearch for a cause of trouble in a vehicle. A case database ismaintained according to the connection of each node according to the“cause” and “effect” relationship.

The user enters “engine” as a search word to this database to identify acause of the engine of a motorcycle not starting, enters “batterywarning lamp” because the battery warning lamp of the Control Panel hasturned on, and enters “starter” and “worse” because the engine does notwork easily even though the starter turns, and then clicks on the searchbutton.

Then the search system searches each node (effect) of the higher layerin the example database with these search words as keywords. As aresult, the nodes “(A-1) engine does not start”, “(B-2) battery warninglamp lighting”, “(B-3) starter is heavy”, and “(B-4) starter does notwork” including one or more of the search words are specified. And, forexample, points are associated with each node according to the number ofsearch words included in each node, such that there is 1 point for node“A-1”, 1 point for node “B-2”, 2 points for node “B-3”, and 1 point fornode “B-4”.

The points of each node are calculated according to the associations(link relations) and the calculation result is given to the node of thebottommost layer of the link. As a result, among the nodes (cause) ofthe bottommost layer, calculation results of 2 points for node “(C-5)trouble of the electric equipment”, 2 points for node “(C-4) trouble ofthe battery”, 1 point for node “(C-2) trouble of the fuel system”, 5points for node “(C-3) battery low”, and 1 point for node “(C-1) fuel isempty” are given,

Therefore, for example, this search system shows a search result of “Isthe amount of charge of the battery too low?” to the user, which is thesearch result having the highest point value, notifies the user of asolution such as “Please charge the battery” that is retained in thedatabase in response to the cause node, or displays the search resultsincluding each cause node sorted sequentially according to points asother possible choices so that the user can understand the points.

In addition, the search system of this embodiment traces the path of alink from a node of the bottommost layer to a node of the topmost layer,and may display this path in order of nodes having higher points. Theuser can review and revise the search conditions and missing links by acomparison among the potential options by displaying the search pathleading to the search results. In this case, the search system maydisplay the paths from the node of the bottommost layer to the node ofthe topmost layer in a list form, or display the paths from the node ofthe bottommost layer to the node of the topmost layer graphically aspart of the forward network structure (refer to FIG. 1). For example, byselecting a node in the bottommost layer that is displayed in the searchresult list above, the search system may display the paths from the nodein the bottommost layer to the nodes in the topmost layer with differentcolors. In this way, the user can know the connections of the nodesincluding the search word at a glance.

In this way, by entering a search word, for example, the search systemof the present embodiment can search for nodes configured hierarchicallyin a cause-effect relationship, and immediately display the result thatthe user wants to know, such as the cause of the effect represented bythe nodes of the bottommost layer.

<Functional Constitution>

FIG. 2 is a figure showing an example of the function blocks in thesearch system of this embodiment. In addition, the function blocks ofthis system described below can be realized as a combination of hardwareand software. Specifically; if a computer is used, the search system mayinclude a CPU and a main memory; a bus; or an auxiliary memory (readingdrives of the memory media such as a hard disk, nonvolatile memory, CD,or DVD); a user interface to control an input device; a printing deviceand a display unit; hardware constitution sections such as other outsideperipheral devices; an interface for the external peripheral devices; aninterface for communication; other application programs and driverprograms to control the hardware, and the like. The arithmeticprocessing by the CPU according to the program developed on the mainmemory causes data input from an input device or another user interfaceand stored in hard disk or memory to be edited, or generates theinstructions for controlling the software and each of the pieces ofhardware. As another example, the function blocks of this system may berealized by exclusive hardware.

In addition, this invention can be realized not only as a system, butalso as a method. In addition, a part of this invention can beconfigured as software. Furthermore, software products used for causinga computer to execute such software and recording media including thesesoftware products are also included in the technical scope of thepresent invention naturally (the same is true through the whole of thisSpecification).

As shown in FIG. 2, a search system 0200 of this embodiment includes aforward network structure information maintenance section 0201, a searchword acquisition section 0202, a node acquisition section 0203, and apoint calculation section 0204.

The forward network structure information maintenance section 0201 has afunction to maintain forward network structure information. The forwardnetwork structure information maintenance section 0201 can beimplemented by an HDD and flash memory, or other various recordingmediums, for example. This “forward network structure information” isinformation that, with stages arranged in a multilayer structure andeach stage including one or more nodes, connects nodes included indifferent layers with each other. For example, the forward networkstructure information may be information that indicates a hierarchicalstructure such as shown in FIG. 1.

This forward network structure may be a general “binary tree structure”,or may be a data structure in which a child node (nodes that are in alower layer) is connected with one or more parent nodes (nodes that arein a higher layer than the child node), such as shown in FIG. 1, and aconnection is formed from a node of the first stage directly to a nodeof the third stage, while skipping over the second stage. As anotherexample, the forward network structure may be such that a node of ahigher layer skips over one or more layers to be connected with a nodeof a lower layer.

The forward network structure information in this embodiment does nothave connections (links) between nodes included in the same layer(stage), and has connections only between nodes of different layers.Each connection between nodes is formed only toward a node included in alower layer from a node included in a higher layer. That is, a one-wayconnection is formed from node A of the n-th layer to node B of the(n+m)-th layer (m is a natural number of 1 or more), and no one-wayconnections are formed from a node of a lower layer to a node of ahigher layer. With the data structure described here, links betweennodes that would form a closed loop are prevented.

The actual data stored in various recording media may be, as shown inFIG. 3A for example, each node-ID, contents of each node (one or morewords associated with the node), and index data associating theinformation indicating the ID of the parent node of the link originand/or ID of the child nodes of the link destination of the node itself.In this way, the data can be configured as a hierarchical structure thatthe computer is able to process, such as shown in FIG. 1. In thisexample, ID associated with the node represents the layer type and theorder or location of the nodes in the layer. Additional informationassociated with the contents of the node may also be included in eachnode. For example, each node can further comprise information of a linkindicating external documents associated with the contents of the node.In this way, it is possible to display more detailed information aboutthe contents of the node.

The forward network structure information may also be maintained as arelational data table in which the primary key is node ID, such as shownin FIG. 3B. In this case, the information indicating the connection(link) between nodes and the contents of the nodes may be stored in adifferent data table. In the example shown in FIG. 3B, the contents ofthe nodes are stored in correspondence with the node ID in a node table,and the connections between nodes are stored in link table.

This index data may show the stage where each node is located. Forexample, in FIG. 1, node “A-1” is in the 1st stage, and nodes “B-1” to“13-4” are in the 2nd stage. Using the information indicating the stage,it is possible to check whether the direction of the connection of thenode indicated by the forward network structure information is anopposite direction, i.e. a direction toward a parent node from a childnode. In this way, it is possible to exclude the opposite-directionconnections, which are the cause of closed loops when tracing theconnections of the nodes at the time of a search.

In this forward network structure information, each “node” mentionedabove is associated with one or more words, and all or part of the nodesare associated with points. That is, the one or more words indicate thecontents of the node. For example, words such as “fuel warning lamplighting”, “engine does not start”, and similar word combinationscorrespond to the words in the example of FIG. 1.

The search system in this embodiment does not limit the one or morewords in particular, but it is desirable for the words to becombinations equivalent to a sentence or to have a meaning equivalent tothat of a sentence. This is because the words that are the contents of atarget node matching the search words have a certain length and number,and having a more semantic association can be expected to improve theaccuracy of search results. In addition, if a computer has enoughprocessing capacity, it is possible to maintain a long sentence or evena document at a node.

As exemplified above, the contents and connections of each node are suchthat nodes of higher layers are associated with nodes of lower layers bythe one or more words in a manner to have a cause and effect or effectand cause relationship, and each of the associated nodes are connected.However, the contents and connections of each node are not limited tosuch a constitution, and can be set appropriately depending on thepurpose or the search object of each search system. For example,relationships such as “an effect” and “a cause”, “an effect” and “aneffect to be caused next”, or “a large classification” and “a smallclassification” can be used. As another example, in the case of arecommended musical piece search for a user in response to a searchword, the association and contents such as “genre—melody—creationdate—title” are assumed. In addition, the contents of each node and theassociation can be created based on knowledge listed in a technicalbook, a manual, or can be created based on knowledge acquired fromexperts of each field. The method to store the contents of each node andthe association as a database is described further below.

Concerning the points associated with a node, which is used for acalculation by a point calculation section described further below,points may be given in each search process according to the result, andmay be given beforehand. The details of the process of setting thepoints for the nodes is described further below when describing thepoint calculation section.

The search word acquisition section 0202 has a function to acquire oneor more search words to use for a search, and can be realized by aninput device for search word input or a search word acquisition programincluding a GUI (Graphical User Interface), for example.

Specifically, on the display of the search system, the GUI image shownin FIG. 4 is displayed, and the user operates an input device, forexample, a keyboard, and enters one or more search words into the searchword input column in the GUI screen. Then, by clicking the search buttonin the GUI screen, the text data input into the input column is acquiredas a search word, and is stored by the “main memory” of the computer. Asanother example, the search word acquisition section may be realized bya microphone and voice recognition software.

There need only be at least one acquired search word, but acquiring twoor more search words is desirable to improve the accuracy of theevaluation of search results according to the point calculation.

In addition, the search word acquisition section 0202 is not limited tothe acquisition by the user input as described above, and may alsoautomatically acquire, as the search words, words obtained throughparsing by applying a computational process to natural sentences thatwere manually or automatically input, or may acquire a search word viacommunication with the Internet or the like. In this case, the searchword acquisition section 0202 may include morphological analyzers or beconnected to a network.

As another example, the search word acquisition section 0202 may receivethe output from the monitors of various systems to acquire a searchword. For example, words such as “temperature of the engine is beyondnormal level” or “consumption of the fuel exceeded the threshold” outputfrom the monitor of a control system of a plane may be acquired assearch words. In this case, the output search word may be a specificcode set beforehand corresponding to contents such as the above.

The node acquisition section 0203 can be realized, for example, by a CPUand a main memory, and includes a node acquisition program having afunction to acquire a node including all or part of the acquired searchwords. In addition, the process of acquiring a node including the searchword should include setting the search word as a search key andperforming the search process for one or more words associated with eachnode.

The phrase “acquire a node including all or part of the search words”may include acquiring a portion of a plurality search words, e.g., nodeA need only include the word “engine” among the search words of “engine”and “worse”, or may include a part of one search phrase, e.g., node Aneed only include “engine” that is a part of the search words “engine isworse”.

This node acquisition section 0203 sets the forward network structureinformation in FIG. 1 as the search target, and acquires nodes “A-1”,“B-2”, “B-3”, and “B-4” as the results by performing a search processwith the search words “engine”, “battery warning lamp”, “starter”, and“worse”.

The point calculation section 0204 has a function to calculate thepoints associated with a node acquired by the node acquisition section0203, in units of nodes of the bottommost layer, among nodes in thepaths tracing connected nodes in the forward network structure. Thepoint calculation section 0204 can be realized by a CPU, main memory,and point calculation program, for example.

Specifically, for example, nodes “A-1”, “B-2”, “B-3”, and “B-4” areacquired by the search process of the node acquisition department 0203for the forward network structure information shown in FIG. 1, and eachnode is given points depending on the number of search words includedtherein. Here, the point relationship is such that node “A-1” has itpoint because one search word (engine) is included therein, node “B-2”also has 1 point for the same reason, node “B-3” has 2 points becausetwo search words (starter and worse) are included, and node “B-4” has 1point.

The arithmetic unit of the search system references the index data shownin FIG. 3A or FIG. 3B and traces the link sequentially, with the node“A-1” shown in FIG. 5A as a start point, for example, and the result ofadding “A-1” (1 point) and “B-1” (0 points) was given to a node “C-1”(there is no gasoline) of the bottommost layer. Similarly, the result ofadding together the sum of “A-1” “B-2” and the sum of “A-1” “B-3” wasgiven to “C-3” (5 points), and the result of adding “A-1” and “B-4” wasgiven to “C-4” and “C-5” (2 points). In the path to “C-3”, two paths(A-1→B-2→C-3) and (A-1→B-3→C-3) exist, but according to this example, itis possible to identify the path (A-1→B-3→C-3) as the path closest to acorrect answer, since this path includes “B-3”, which has more searchwords.

In this way, the point calculation section 0204 assumes node “A-1” as astart point in the manner described above and may have a downwarddirection calculation means to trace the nodes towards the bottommostlayer from the topmost layer, and to perform calculation processing. Asanother example, the point calculation section 0204 may assume a lowerlayer node as a start point and have an upward direction calculationmeans to trace the nodes towards the topmost layer from the bottommostlayer.

FIG. 5B is a figure to explain point calculation in detail. The nodeacquisition section 0203 acquires a node including all or part of theacquired search words, with reference to forward network structureinformation maintenance section 0201. FIG. 5 shows an example in whichthe search words included in nodes “A-2” and node “B-3” were acquired,and the node acquisition section 0203 acquires nodes “A-2” and “13-3”including the search word. Next, the point calculation section 0204chooses the node of a bottommost layer that is connected with the mostnodes in the paths that trace the connected nodes acquired by nodeacquisition section 203, with reference to the forward network structureinformation maintenance section 0201, from the topmost layer in theforward network structure to the bottommost layer, and is connected. Inthis example, the point calculation section 0204 identifies seven pathsthat include node “A-2” and node “B-3” to be (path 1: A-1→B-3→C-3);(path 2: A-1→B-3→C-4); (path 3: A-2→B-3→C-3); (path 4: A-2 B-3→C-4);(path 5: A-2→B-4→C-4); (path 6: A-2→B-4→C-6); (path 7: A-2→B-5→C-5), andcalculates the points at each node of the bottommost layer. Because thelargest number of nodes (node A-1; A-2; B-3; B-4) is connected with node“C-4” in the bottommost layer among these seven paths, the pointcalculation section 0204 chooses node “C-4”. In other words, three pathsincluding paths 2, 4, and 5 exist as paths to C-4, but according to thisexample, the point calculation section 204 identifies path 4, which isthe path including the nodes (A-2 and node B-3) having more searchwords, as the path that is closest to a correct answer. By using such analgorithm, it is not necessary to calculate the points of all paths andthe computational complexity can be reduced.

In this example, the points associated with a node are decided accordingto the number of search words, but various applications are possible.For example, points may be added depending on the importance that theuser thinks a search word has. As another example, points that areweighted with values such as 1-5 may be added depending on theimportance that the user thinks a search word has. The search word thata user thinks to be more important is given a high point value, andtherefore the search results after the calculation reflect the opinionof the user.

The points associated with a node may be a value that was calculatedfrom the number of search words, and need not be the number itself. Forexample, values that are revised according to the weighted value forevery search word based on the number of search words may be used. Inthis case, a table that associates a weighted value with a search wordbeforehand and is held and referred to. In addition, a different tablemay be used for the weighted value depending on the search purposes, forexample. The table may be such that, concerning search words such as“engine” and “heavy” in a search for a cause of trouble, “engine” isgiven a small weighted value because it is a word often acquired by allsearches for trouble, while “heavy” is given a large weighted valuebecause it shows a specific phenomenon of trouble. As another example, atable may be such that, in a car model search to decide on a vehicle topurchase, “engine” is given a large weighted value because it is animportant part of the vehicle, while “heavy” is given a small weightedvalue because the importance for determining a purchase is low. Thetable to be used may be determined with reference to search purposeinformation that is acquired through user input at the time of thesearch.

In addition, the points associated with a node may be established basedon attribute information that was prepared beforehand relating to thesearch word. Attribute information may be information unique to a searchpurpose or to a search target. For example, because the search system ofthis example is a system to search for a cause of trouble, the systemmay have attribute information such as “trouble”, “deterioration”,“life”, “price”, and “importance” for every search word beforehand, andeach type of attribute information is given a weighted value beforehand.The points are calculated based on each weighted value corresponding tothe attribute information that the search word “engine” has. Thesevalues may use a normalized value (0-1). For example, the value may becalculated as F (node)=Σn (trouble rate+deterioration timecoefficient+life coefficient+price+importance). Here, “n” shows thenumber of search words included in the node. Specifically, whencalculating “the risk that engine trouble gives in the whole system”(the risk that engine trouble gives in the whole system)=1.2 (enginetrouble rate)+1.1 (deterioration time for engine coefficient)+1.3 (lifecoefficient of the engine)+20 (price of engine coefficient)+3.0(importance of the engine)=8.6.

In addition, more than one sentence may be included as the contents of anode. In such a case, for a sentence associated with one node, aplurality of search words may be a match. In this case, the pointcalculation section 0204 may give a larger weight value to nodes thatinclude more search words.

The points are not limited to being dependent on the number of thesearch words included in the node. For example, preliminarily points maybe associated with nodes uniformly or depending on the content, and thepoints may be calculated, as described in Embodiment 2 further below.

Based on the points calculated in this way, the search system of thisembodiment shows that the content “Charge quantity of the battery may below” of the node having the highest point value in the bottommost layeris the search (the reasoning) result of highest accuracy. For example,as shown in FIG. 6, a conformity rate is calculated to express accuracyof the reasoning from the points calculated for every node of thebottommost layer, and the results obtained by ordering all or part ofthe nodes of the bottommost layer sequentially from the highestconformity rate that was calculated (result display section).

In addition, this result display section may have a higher layer displaymeans to display a list of the contents or one or more words associatedwith the nodes of the higher layers that are connected with each of thenodes of the bottommost layer, for each node in the bottommost layer.The effects of such a display are that, for example, the user canreference the lists to confirm the contents of the higher layer nodesconnecting to the bottommost layer node that was a correct answer, andif there is a node that contains contents other than the search wordsthat was entered, can expect to find search words included in thecontent that have been overlooked as keywords.

As another example, a mother may search for a disease contracted by herchild using the search words “fever” and “vomiting”, and when “mumps”and “campylobacter enteritis” are displayed as the results with equalpoints, the contents of nodes of the higher layers that are associatedwith each result are displayed as a list. Then in addition to the nodes“fever” and “vomiting”, the nodes having contents such as “chills” and“headache” are associated with the “mumps”. On the other hand, inaddition to the nodes “fever” and “vomiting”, the nodes having contentssuch as “diarrhea” and “hematochezia” are associated with “campylobacterenteritis”.

Therefore the mother watches for changes in the symptom of the child,and it is possible to confirm whether these signs are present and judgewhich disease it is, or to care for these symptoms and nurse the child.

In addition, if the search is performed using a search word output bythe monitor of the control system of the above-mentioned plane, a pilotcan be notified of search results such as “abnormality of the jetcontrol valve of the engine”, which has the highest calculated pointvalue, via audio output, and a flashing control signal of a warning lampthat was established on the operation panel of the plane to notify thepilot about “abnormality of the jet control valve of the engine” may beoutput.

According to the configuration described above, when a search word isentered, for example, the node group that was constructed to beassociated with a condition such as “cause and effect” in thehierarchical forward network structure is searched, the path of thelinkage is traced, and the points of each node can be calculated inunits of nodes of the bottommost layer. Therefore, the user can know thecauses of the effects shown in the node of the bottommost layer havingthe highest point value immediately; without taking the trouble such asseen in the inquiry type of search described above.

As another example, the nodes of the bottommost layer can be orderedaccording to their points, and a user can be presented with the causesshown by the plurality of ordered nodes of the bottommost layer. Whenthere are a plurality of search results, it is possible to present auser with ordering that indicates the possibility of an answer in thesearch being correct.

It is also possible to display the contents (one or more associatedwords) of the nodes of the higher layers as a list, for every node ofthe bottommost layer. The user can refer to the list, for example, andconfirm the contents of the higher layer nodes connected to thebottommost layer node that was a correct answer, and therefore theeffect finding search words that were overlooked can be expected.

<Modification 1>

In a case of HTML documents connected with links on the Internet, it ispossible to assume a forward network structure in which a given HTMLdocument is a node of the topmost layer, and the HTML documents that arelinked directly thereto are nodes of the second layer. For example, akeyword or description of the HTML document is acquired as characterstrings to create the content corresponding to the node. In addition, alink URL described in a document is registered with the forward networkstructure information maintenance section 0201 as link informationindicating the association with other nodes. The registration in theforward network structure information maintenance section may beperformed by manual operation, or by using an editing means explained inconjunction with FIG. 11A and FIG. 119.

As another example, when recommended books are associated with Internetsearch results, it may be assumed that the recommended books are nodesof the bottommost layer, and the recommended books may be presented inorder according to the points calculated by this search system.Furthermore, “the number of the keyword access” may be used as attributeinformation when using an HTML document on the Internet as a node, suchas in this example.

<Modification 2>

As a modification of the present embodiment, the points mentioned abovemay be calculated in units of the nodes in a predetermined middle layer,instead of in units of the nodes in the bottommost layer. In this case,the point calculation section 0204 may calculate the points associatedwith a node acquired by the node acquisition section 0203, among thenodes in the paths that trace the connected nodes, in units of nodes inthe predetermined middle layer in the forward network structure. The“predetermined middle layer” may be a reception layer (e.g., a layerincluding the node designated by input to directly appoint a layernumber or by user input concerning the contents of the node) by userinput through GUI screens, or may be a layer set beforehand.

As another example, when a node including all or part of the searchwords is acquired by node acquisition section 0203, the pointcalculation section 0204 may perform the calculation in units of nodesin the lowest layer where a node that includes all or part of the searchwords was found, or may perform the calculation in units of nodes thatare in a layer at least one level lower than the layer mentioned above.In other words, when an input search word is acquired and the lowestlayer node is in the m-th layer, the predetermined middle layer may bethis m-th layer, the (m÷1)-th layer, the (m+2)-th layer, or any layerlower than this.

When the object of the search has a very complicated structure such asthe hierarchy structure used to identify trouble in the large-scaleplant, the degree of association between the contents of a node of them-th layer and a node of the bottommost layer may be low. However,according to the constitution mentioned above, the user can find arequested result easily by pinpointing the layer in which calculation isto be performed, even if the object of the search system is verycomplicated.

The “result display section” may display the ordered results for all orpart of the nodes connected with the layers lower than the predeterminedmiddle layer, using the points calculated tier every node of thepredetermined middle layer.

Specifically, for example, in the forward network structure informationused for a disaster simulation search system, nodes are connecteddepending on a change over time of contents, such that the node of the1st layer “wind velocity>60 m/s” is connected to the 2nd layer nodes“service stop of the main route” and “20% of fallen trees”. Among nodesthat include search words such as “wind velocity of 65 m/s” and“Yamanote train line has halted operation,” the points are calculatedwith the lowest layer including one of these nodes set as thepredetermined intermediate layer. Continuing with this example, the 3rdlayer nodes “lack of supplies” and “outbreak of return refugees” thatare connected, based on the change over time, with a node in a layerbelow the node “operation halted on the main route” having 5 points aredisplayed as search results having 5 points. In addition, the 3rd layernode “outbreak of an injured person on the way home” that is connected,based on a change over time, with layers lower than the node “20% offallen trees” having 2 points, are displayed as search results having 2points.

In this way, for example, nodes in the forward network structureinformation are connected according to a change over time of thecontents of the nodes, and by calculating the points in units of nodesin the predetermined middle layer in the forward network structure, itis possible to predict the possibility of future effects occurring.

<Hardware Configuration>

FIG. 7 is a schematic view that shows an example of the constitution ofthe search system when each functional element mentioned above isrealized as hardware. Using this figure, an explanation of the functionof each hardware element in the search process using point calculationof the nodes is provided.

As shown in FIG. 7, the search system of the present embodimentcomprises a CPU 0701 and a main memory 0702, which carry out operationsand processing to realize the functions of a node acquisition section, apoint calculation section, and various other functions. In addition, thesearch system comprises a forward network structure informationmaintenance section HDD 0703, a search word acquisition section 0202that is the keyboard, an input device 0704 that includes various otheruser input devices, and a display section 0705 that displays searchresults. These components are connected to each other by datacommunication paths such as “system buses,” and perform transmission,reception, and processing of information.

A program is read in the main memory 0702, and the CPU0 701 referencesthe read program and executes various operational processes according toa programmed procedure. In addition, a plurality of addresses areassigned to storage devices such as this main memory 0702 or the HDD0703, and in the operation processing of CPU 0701, the operationalprocessing using data can be performed by identifying the address andaccessing the stored data.

Here, for example, the forward network structure information isgenerated by automatically analyzing the input by the operator or theacquired sentence using morphological analysis technology, and recordedin the HDD 0703. Specifically, when an operator inputs one or more wordsconnected with each node or inputs information to designate a linkstructure indicating the connections between nodes, the index data shownin FIG. 3A or FIG. 3B is generated by an operation of the CPU 0701 andrecorded in the HDD 0703. As another example, when the search systemacquires a phrase such as “when the engine does not start, causes suchas (1) lack of gasoline, (2) lack of battery charge, (3) damage to thestarter, etc. can be imagined. In the case of (1), the fuel warning lamp. . . ”, a morphological analysis is performed on this phrase and aprocess is performed to generate and determine the connection of nodesaccording to the meaning of this phrase, thereby generating index datathat is then stored in the HDD 0703.

After this, when a user starts the search system, the CPU 0701interprets a search word acquisition program and displays in the display0705, for example, the GUI screen shown in FIG. 4. The CPU stores thewords that the user input into the input column in the screen, e.g.,“engine”, “battery warning lamp”, “starter”, or “heavy” at apredetermined address in the main memory 702, as search words.

Then, the CPU 0701 interprets a node acquisition program, and accordingto the interpretation result, acquires each search word that was storedin the main memory 0702 as a search key and, with the forward networkstructure information maintained by the HDD 0703 as a search target,executes processing similar to the conventional search processing. TheCPU 0701 identifies the ID of the node including the search word inconjunction with the number information (points) of the search wordsincluded in the contents and stores each ID in a predetermined addressof the main memory 0702.

Next, the CPU 0701 interprets a point calculation program, and accordingto the interpretation result, references the forward network structureinformation and acquires the path (link relations) indicated by theconnections of nodes stored in the main memory 0702. Among the nodes inthe acquired path, the points associated with nodes stored in the mainmemory 0702 are calculated by operational processing of the CPU 0701 inunits of the nodes of the bottommost layer. The calculated results areeach stored in a predetermined address of main memory 0702, inassociation with the IDs of the nodes of the bottommost layer.

Finally, the CPU 0701 interprets a search result display program, andaccording to the interpretation result, for example, displays thecontents of the nodes with the highest point values in the display 0705,or displays the ordered results for some or all of the nodes in thebottommost layer as a list in the display 0705, according to the points.

In addition, the search system can be realized through the Internet,such as shown by the other constitution example 1. Specifically, forexample, the input device 704 and display 0705 are provided in aterminal of the user, other components are installed in the server, andthese components are connected to each other through the Internet. Inthis case, the components (CPU 0701, main memory 0702, HDD 0703) may bearranged in one server on the network, or may be dispersed and locatedin a plurality of servers.

<Process Flow>

FIG. 8 is a flow chart showing an example of the flow of the processingperformed by the search system of this embodiment. The steps shown belowmay be executed by each piece of hardware constituting the computer,such as described above, or a program may be recorded on a medium andused to cause each step to be executed, by controlling a computer.

As shown in FIG. 8, first, associations are formed with one or morewords, and with a multilayer structure of stages which include one ormore nodes that are associated all or in part with points, the forwardnetwork structure information is recorded in the forward networkstructure information maintenance section to maintain the forwardnetwork structure information in which the nodes included in differentstages are connected to each other (step S0801).

In the search system maintaining this forward network structureinformation, for example, one or more search words, which are the wordsused for a search, are acquired via user input, input resulting fromautomatic analysis of a sentence, or input through the communicationcircuit (step S0802), and through the search operation process ofarithmetic units, nodes including all or part of the acquired searchwords are acquired (step S0803).

Next, among the nodes in the paths tracing connected nodes in theforward network structure, points associated with nodes acquired in thenode acquisition step are calculated in units of nodes of the bottommostlayer (step S0804), and the contents relating to the nodes of thebottommost layer having the highest point values according to theacquired points are displayed, or the nodes of the bottommost layer aredisplayed in a list, with an order according to the points.

With this constitution, by entering search words, for example, a searchis performed for nodes arranged to have a “cause and effect”relationship in a hierarchy, and the user can immediately know thecauses of the effects shown in the nodes of the bottommost layer.

In addition, since the nodes of the bottommost layer can be orderedaccording to the points, the ordered search results can be presented tothe user.

Embodiment 2

<Overview>

The present embodiment is based on the embodiment mentioned above, andthe search system is characterized by the feature that the pointsassociated with the nodes are not associated according to the number ofsearch words included in the nodes after the search using the searchwords, and are instead associated in a database beforehand, and that theassociations can be modified appropriately according to the feedback ofsearch results.

<Functional Constitution>

FIG. 9 is a figure showing an example of the function blocks in thesearch system 0900 of this embodiment. As shown in this figure, thesearch system 0900 of this embodiment has, on the basis of embodiment 1,a forward network structure information maintenance section 0901, asearch word acquisition section 0902, a node acquisition section 0903,and a point calculation section 0904. In addition, the search system0900 may have a “calculation means for lower parts” or a “resultindication section”, which are not shown.

The forward network structure information maintenance section 0901further includes a point maintenance means 0905 and point modificationmeans 0906 in the search system of this embodiment.

The point maintenance means 0905 has a function to maintain the pointsassociated with the nodes together. Specifically, for example, among theitems of the index data of FIG. 3A or FIG. 3B, an item storing thepoints established beforehand is prepared, the nodes may be given thesepoints uniformly; such that each node has 10 points, or different pointsmay be given to each node, and this association between points and nodesis maintained.

The point modification means 0906 has a function to modify the pointsmaintained by the point maintenance means, and can be realized by a CPU,a main memory; and a point modification program, for example.

More specifically, for example, a user is presented with the contents ofthe bottommost layer nodes that are ordered according to the calculatedpoints by the result indication section, and the user inputs the actualcorrect answer (the products which the user actually liked if it was arecommendation search, or a cause of the actual trouble if it was atrouble search). When the node ID of the correct answer acquired in thismanner is different from the highest point node ID, the point valuesthat is associated in advance with the nodes relating to the link ofthis node in the bottommost layer are modified to be reduced, while onthe other hand, the point values of the nodes relating to the link withthe node in the bottommost layer that is the correct answer are modifiedto be increased.

As another example, the user may be shown the contents of the bottommostlayer node that has the highest point value, and the user may input ananswer concerning whether this content is correct or not, and if it is“incorrect”, then the points associated in advance with the noderelating to the link of the node of the bottommost layer may be modifiedto be reduced.

As another example, instead of modifying the points associated with anode beforehand, a constitution may be used in which the link relationsand the contents of the nodes are edited depending on the pointcalculation and the answer input.

In addition, the search system of this embodiment additionally may havea “point modification means control section”, not illustrated. The“point modification means control section” has a function to modify thepoints that are associated with a node, using all or part of the searchwords acquired by the search word acquisition section either directly orindirectly. For example, the point modification means control sectioncan be realized by a CPU, a main memory, and a point modification meanscontrol program.

Specifically, for example, modification can be performed by decidinglarge and small values for point modification values directly accordingto the number of search words included in the nodes, or the modifiedvalue can be indirectly determined and modified using a factor (e.g., afactor that is high for a noun or verb that relates closely to thesearch target) indicating importance set for a search word beforehand.

<Process Flow>

FIG. 10 is flow chart showing an example of the flow of the processingin the search system of this embodiment. In addition, the steps shownbelow may be executed by each piece of hardware constituting thecomputer such as described above, or a program may be recorded on amedium and used to cause each step to be executed, by controlling acomputer. In addition, the steps relating to the point calculationprocessing of the bottommost layer nodes are the same as those describedin the embodiment described above, and therefore a description thereofis omitted.

As shown in this figure, through the processing described in embodiment1, the points are calculated in units of the nodes of the bottommostlayer (step S1001). Search results are displayed depending on theacquired points, and input of an answer to show whether the result is acorrect answer is received (step S1002). The points are then modifieddepending on the answer input (step S1003).

As described above, in this search system of the present embodiment, thepoints associated with nodes in a database beforehand can be modifiedappropriately by the feedback of search results, and therefore the rateof matching in the search results can be improved.

The search systems 0200 and 0900 explained using FIG. 2 and FIG. 9 mayhave a node contents editing means to edit the contents of nodesmaintained by the forward network structure information maintenancesection, and a link editing means to edit the connections (links)between the nodes. FIG. 11A shows an example of a node contents editingscreen 1100 to make a new node and to edit the contents of the node. Inaddition, FIG. 11B shows an example of a link editing screen 1150 toedit the connection between the nodes.

The node contents editing screen 1100 has a node attribute entry section1102, a node ID indication section 1104, a search button 1106, aregistration button 1108, a modification button 1110, a deletion button1112, and a reference entry section 1114. The node contents editingmeans lets the user (e.g., an expert) input the information “engine doesnot start” as content of the nodes into the node entry section 1102 andadds a unique ID for this input content. The node contents editingmeans, for example, adds the node ID by having the user click theregistration button 1108 in the editing screen 1100, and may store thenode ID and contents of the node in the table described in FIG. 3A orFIG. 3B. This example of the node contents editing means has a functionto search the contents of a stored node and a function to modify and todelete these contents.

The node contents editing means may have a function to let the forwardnetwork structure information maintenance section record additionalinformation in conjunction with the contents of the node to beregistered. For example, when there are books related to the contents ofthe node, the node contents editing means lets the user input referenceinformation (book title, author name, reference page, etc.) of therelated book into reference entry section 1114 and records theinformation that was input in the forward network structure informationmaintenance section, in correspondence to the node.

The link editing screen 1150 has a higher node keyword input section1152, a higher node list indication section 1154, a lower node keywordinput section 1156, a lower node list indication section 1158, a searchbutton 1160, a registration button 1162, and a deletion button 1164. Thelink editing means lets a user identify nodes of the higher layers or ofthe lower layers that are connected to the target node, to add, change,or modify the connections of the nodes. In this example, the link,editing means identifies the node including a keyword input into thehigher node keyword input section 1152, and displays a list ofidentified higher nodes in the higher node list display section 1154.Similarly, the link editing means displays a list of lower nodes in thelower node list display section 1158. Furthermore, a connection isformed between a lower node and a chosen higher node when a user clicksthe registration button 1160. In this way, the link editing means lets auser choose a higher node and a lower node to be connected to eachother.

In the example of FIG. 11B, the user inputs the information such as“engine” for a higher node keyword and “starters” for a lower nodekeyword, in order to search the nodes. When the user clicks the searchbutton 1160 in a node editing screen, a list of the node informationmatching the higher node keyword, such as “engine does not start” isdisplayed in a higher node list. As for the registration of the link,when “engine does not start” is chosen from the higher node list and“starter is heavy” is chosen from the lower node list and theregistration button 1162 is clicked, the link table of FIG. 3A or FIG.3B is created. As for the deletion of a link, a part of the nodeinformation is entered, and by clicking the search button 1160, the linktable and node table in FIG. 3A or FIG. 3B are searched. The node listis then displayed, the user selects a higher node of the higher nodelist and a lower node of the lower node list, and the deletion isexecuted by clicking the deletion button 1164.

FIG. 12 shows an example of the function blocks in the search system1200 of embodiment 3. The search systems described in embodiment 1 andembodiment 2 have a case example database for one category, which is“trouble of a vehicle”, but this search system 1200 differs from theseembodiments by having a plurality of case example databases relating toa plurality of categories.

The search system 1200 comprises a forward network structure informationmaintenance section 1201, a search word acquisition section 1202, a nodeacquisition section 1203, a point calculation section 1204, a pointmodification means control section 1208, and an editing section 1212.The forward network structure information maintenance section 1201 has apoint maintenance means 1205, a point modification means 1206, and aplurality of memory means 1210. For example, the memory means 1210 is anHDD. The node acquisition section 1203 has a category selecting means1207, an editing section 1212, and a node contents editing means 1214.

In addition, the search word acquisition section 1202, node acquisitionsection 1203, point calculation section 1204, point maintenance means1205, point modification means 1206, and point modification meanscontrol section 1208 have functions similar to those of the forwardnetwork structure information maintenance section 0201, search wordacquisition section 0202, node acquisition section 0203, and pointcalculation section 0204 explained in embodiment 1, and the pointmaintenance means 0905, point modification means 0906, and pointmodification means control section (not shown) explained in embodiment2. Furthermore, the node contents editing means 1214 and link editingmeans 1216 have functions similar to those of the node contents editingmeans and link editing means explained in FIG. 111A and FIG. 11B.Therefore, explanation of these components is omitted.

The forward network structure information maintenance section 1201stores a plurality of pieces of forward network structure information.In this example, the forward network structure information is stored inthe plurality of memory means 1210 for every category. For example, theforward network structure information is classified in categories suchas “disease of an infant”, “car”, and “plant”. Each node included in acategory has the information of this category as node informationbeforehand.

When a search word is input, the node acquisition section 1203 acquiresa node including all or part of the search words acquired by the searchword acquisition section 1202. When the node acquisition section 1203acquires a plurality of nodes included in a plurality of categories, thecategory selection means 1207 identifies the category that each acquirednode belongs to and shows this information to the user. For example, thecategory selection means 1207 may display a list of identifiedcategories corresponding to a chosen category. When a user selects adesired category from among the list of displayed categories, thecategory selection means 1207 identifies the forward network structureinformation, which is a database corresponding to the selected category,the node acquisition section 1203, in the subsequent processing,acquires the nodes from the forward network structure informationcorresponding to the identified category, and the point calculationsection 1204 calculates the points in the manner described above. Ahigh-precision search can be performed in this way. Furthermore,searches in multiple fields or categories can be processedsimultaneously in parallel, by using a plurality of servers configuredto process each category. For example, in a case where a search word isincluded in a plurality of categories, the category selection means 1207may perform the search in each of these categories simultaneously. Inthis case, the forward network structure information maintenance section1201 may include a plurality of pieces of forward network structureinformation divided according to predetermined categories, the categoryselection means 1207 may select the pieces of forward network structureinformation corresponding to these categories, and the point calculationsection 1204 may perform calculation using the selected pieces offorward network structure information. For example, if the search wordis “rash”, the search can be performed in a plurality of specializedcategories such as “makeup products”, “dermatology”, “internal illness”,or “cancer”, and a variety of unexpected results can be presented to theuser.

FIG. 13 shows an example of the search system using the cloud. Thesearch system 1300 includes a user terminal 1302, an access provider1304, a search server 1306 for Japanese language, a search server 1308for foreign languages, and a plurality of servers 1310-1316. The searchserver 1306 for Japanese language is a server to search in the Japaneselanguage and has a security check section 1318 and a search section1320. The search server 1306 for Japanese language and the search server1308 for foreign languages may be located in Japan or may be located ina foreign country; and each server may be located in a differentcountry.

The search section 1320 includes a search word acquisition section 1202,a node acquisition section 1203, a point calculation section 1204, andan editing section 1212 that have been explained above. The previouslydescribed plurality of pieces of forward network structure informationincluded in the forward network structure information maintenancesection 1201 are installed in the different servers 1310 and 1312according to each category. The search server 1308 for foreign languagesis a server to perform searches in foreign languages, and has atranslation section 1322 and a search section 1324. The search section1324 includes a search word acquisition section 1202, a node acquisitionsection 1203, a point calculation section 1204, and an editing section1212.

In this example, the previously described plurality of pieces of forwardnetwork structure information included in the forward network structureinformation maintenance section 1201 are installed in the differentservers 1310-1316 according to each category. Furthermore, the contentof nodes included in the forward network structure information of thesame category is created in different languages, and is stored indifferent servers according to each language. In this case, the servers1310-1316 may each be installed in the country corresponding to thelanguage thereof, or may be installed in the country where the searchwords are input.

In this example, when the security check section 1318 receives an accessrequest from the user terminal 1302 through the access provider 1304,the security check section 1318 performs the login processing to thesearch system. The translation section 1322 translates the search wordof a predetermined language input from the user terminal 1302 into otherlanguages and transmits these translated words to the search wordacquisition section 1202 of the search section 1324. Thus, the searchsection 1324 can perform a search using the forward network structureinformation containing nodes that were created in a foreign language andstored in the overseas servers 1314 and 1316.

The search section 1320 makes an inquiry about an input search word toeach server 1310-1316. When a search word matches one category, thesearch section 1320 performs the point calculation process, and the userterminal 1302 displays the result. On the other hand, when the searchword matches a plurality of categories, the search section 1320 lets theuser terminal 1302 display the list of matching plurality of categories,and the user terminal 1302 lets a user select a category to perform thepoint calculation process. In this way, useless processing is reducedand the user can get the needed result quickly. In addition, the searchsection 1324 may have a function similar to that of the search section1320. In addition, this system may be opened to the public on theInternet and may link the opinions of agreement or disagreement for eachindividual person about a specific proposition. In this way; unlike aconventional one-dimensional link such as Twitter, it is possible tocomprehend the expansion and directional trend of an argument in atwo-dimensional visual manner.

The security check section 1318, search section 1320, search section1324, and translation section 1322 are located in two different serversin this example, but these sections may instead be implemented in oneserver, or may be implemented in three or more servers. In addition, thecountry where a server is located is not limited to any particularcountry.

The above explained a search system of this invention using embodiments1 to 3. However, the search technology used by the search system of thisinvention is not limited to a direct search to identify “a cause” thatcauses “trouble”. For example, the search system may compile existingtheses into a database with the forward network structure and examinethe connections (links) between nodes, so that researchers can use thissystem as a search tool for finding a new study proposition byidentifying something that is lacking in the connections between nodes.A portion lacking in the links may be confirmed by displaying an errormessage to a user, or this portion may be detected automatically byusing an algorithm. The tacking portion of a link may be compensatedwith an association of similar words by using a thesaurus, or by using“number of keyword accesses” as association information, in order toanalyze the correlation coefficient between search words by factoranalysis of multivariate statistics, thereby automatically detectingmissing links. In addition, looping is not permitted when forming alink, because the connections (links) between nodes in the forwardnetwork structure information are always formed in one direction towarda lower layer from a higher layer. The link editing means 1216 describedabove may be constructed such that an error message is displayed whentrying to form a connection toward a node in a higher layer from a lowerlayer node. Thus, it is possible to use the link editing means 1216 toperform a loop check in complex logic.

The present invention has been described using the embodiments shownabove, but the technical range of this invention is not limited to theembodiments described above. It is apparent to those skilled in the artthat it is possible to make a variety of changes or improvements to theembodiments described above. It is also apparent from the scope of theclaims that the embodiments added with such alterations or improvementscan be included in the technical scope of the invention.

The operations, procedures, steps, and stages of each process performedby an apparatus, system, program, and method shown in the claims,embodiments, or diagrams can be performed in any order as long as theorder is not indicated by “prior to,” “before,” or the like and as longas the output from a previous process is not used in a later process.Even if the process flow is described using phrases such as “first” or“next” in the claims, embodiments, or diagrams, it does not necessarilymean that the process must be performed in this order.

What is claimed is:
 1. A search system comprising: a forward networkstructure information maintenance section that, with stages arranged ina multilayer structure and each stage including one or more nodesassociated with one or more words and associated in whole or in partwith a point, maintains forward network structure information thatconnects nodes included in different layers with each other, in orderfrom a higher layer toward a lower layer in a network state; a searchword acquisition section acquiring one or more search words to use for asearch; a node acquisition section having means to acquire a nodeincluding all or part of the acquired search words and to convert theacquired search words into a point; a point calculation section that,using the forward network structure information, calculates points bysequentially adding together in a manner to inherit points, in nodeunits of each layer, the points associated with the nodes acquired bythe node acquisition section along all of the paths connected by thesepoints from a topmost layer to the node of a predetermined layer; and adisplay control section that controls display of the result obtained byordering all or part of the nodes in the predetermined layer, using thepoints that have been calculated for each node in the predeterminedlayer.
 2. The search system according to claim 1, wherein among thenodes forming the multilayer structure in which the forward networkstructure information maintenance section maintains the forward networkstructure information, (i) a connection is formed from each of the atleast one or more nodes included in any one of the plurality of layersexcept the bottommost layer, toward at least one or more nodes includedin one or more layers at a lower position than the one layer, and eachof the one or more nodes in the one layer is connected to neither thenodes in the one layer nor nodes in the higher layers, or (ii) aconnection is formed from each of the at least one or more nodesincluded in any one of the plurality of layers except the topmost layer,toward at least one or more nodes included in one or more layers at ahigher position than the one layer, and each of the one or more nodes inthe one layer is connected to neither the nodes in the one layer nornodes in the lower layers.
 3. The search system according to claim 2,wherein the connection is formed from each of the plurality of nodesincluded in the one layer of the plurality of layers and/or from one ormore nodes included in different layers of the plurality of layers. 4.The search system according to claim 1, wherein among the nodes formingthe multilayer structure in which the forward network structureinformation maintenance section maintains the forward network structureinformation, nodes of higher layers are connected with nodes of lowerlayers by the one or more words in a manner to have a cause and effector effect and cause relationship, or the nodes of the lower layers areconnected with the nodes of the higher layers by the one or more words.5. The search system according to claim 1, further comprising a means toexclude opposite-direction connections, which are a cause of closedloops when tracing the connections of the nodes at the time of a search.6. The search system according to claim 1, wherein the point calculationsection has a means to identify, among a plurality of paths tracingconnected nodes acquired by the node acquisition section from thetopmost layer to a predetermined layer in the forward network structureinformation, the node associated with the largest point value in thepredetermined layer and all of the paths associated with the identifiednode.
 7. The search system according to claim 1, wherein the displaycontrol section has a means to display a path and a means to display, asa list for each node of a predetermined layer, one or more wordsassociated with nodes of the higher layers and the lower layers that areconnected to the nodes of the predetermined layer.
 8. The search systemaccording to claim 1, further comprising a point modification meanscontrol section that determines and modifies a point value at apredetermined node, by using all or part of the search words acquired bythe search word acquisition section or by using an importance factor setin advance in association with a search word through user input orfeedback of the search result.
 9. The search system according to claim1, wherein the search word acquisition section further includes aninterface to directly acquire output from other system control units.10. A display unit for displaying the results output by the searchsystem according to claim
 1. 11. A computer-readable recording medium onwhich is recorded data having a data structure that contains a hierarchyof a plurality of nodes and a plurality of layers, wherein each of theone or more layers has at least one or more nodes, the nodes areassociated with one or more words and associated in whole or in partwith a point, and (i) a connection is formed from each of the at leastone or more nodes included in any one of the plurality of layers exceptthe bottommost layer, toward at least one or more nodes included in oneor more layers at a lower position than the one layer, and each of theone or more nodes in the one layer is connected to neither the nodes inthe one layer nor nodes in the higher layers, or (ii) a connection isformed from each of the at least one or more nodes included in any oneof the plurality of layers except the topmost layer, toward at least oneor more nodes included in one or more layers at a higher position thanthe one layer; and each of the one or more nodes in the one layer isconnected to neither the nodes in the one layer nor nodes in the lowerlayers.
 12. An apparatus having a data structure that contains ahierarchy of a plurality of nodes and a plurality of layers, whereineach of the one or more layers has at least one or more nodes, the nodesare associated with one or more words and associated in whole or in partwith a point, and (i) a connection is formed from each of the at leastone or more nodes included in any one of the plurality of layers exceptthe bottommost layer, toward at least one or more nodes included in oneor more layers at a lower position than the one layer, and each of theone or more nodes in the one layer is connected to neither the nodes inthe one layer nor nodes in the higher layers, or (ii) a connection isformed from each of the at least one or more nodes included in any oneof the plurality of layers except the topmost layer, toward at least oneor more nodes included in one or more layers at a higher position thanthe one layer, and each of the one or more nodes in the one layer isconnected to neither the nodes in the one layer nor nodes in the lowerlayers.
 13. A search system comprising: a means that displays a screenfor acquiring one or more search words to use for a search; and a meansthat, upon receiving input of a search word from a user, acquires pointsfrom a forward network structure information maintenance section that,with stages arranged in a multilayer structure and each stage includingone or more nodes associated with one or more words and associated inwhole or in part with a point, maintains forward network structureinformation that connects nodes included in different layers with eachother, in order from a higher layer toward a lower layer in a networkstate, where the points correspond to a node including all or part ofthe input search words that are acquired, calculates points bysequentially adding together in a manner to inherit points, in nodeunits of each layer, the points associated with the nodes along all ofthe paths connected by these points from a topmost layer to the node ofa predetermined layer, and displays a result of ordering all or part ofthe nodes of the predetermined layer using the acquired points.
 14. Thesearch system according to claim 13, wherein among the nodes forming themultilayer structure in which the forward network structure informationmaintenance section maintains the forward network structure information,(i) a connection is formed from each of the at least one or more nodesincluded in any one of the plurality of layers except the bottommostlayer, toward at least one or more nodes included in one or more layersat a lower position than the one layer, and each of the one or morenodes in the one layer is connected to neither the nodes in the onelayer nor nodes in the higher layers, or (ii) a connection is formedfrom each of the at least one or more nodes included in any one of theplurality of layers except the topmost layer, toward at least one ormore nodes included in one or more layers at a higher position than theone layer, and each of the one or more nodes in the one layer isconnected to neither the nodes in the one layer nor nodes in the lowerlayers.
 15. A method comprising: maintaining forward network structureinformation that, with stages arranged in a multilayer structure andeach stage including one or more nodes associated with one or more wordsand associated in whole or in part with a point, connects nodes includedin different layers with each other, in order from a higher layer towarda lower layer in a network state; acquiring one or more search word touse for a search; acquiring a node including all or part of the acquiredsearch words and converting the acquired search words into a point;using the forward network structure information to calculate points bysequentially adding together in a manner to inherit points, in nodeunits of each layer, the points associated with the acquired node alongall of the paths connected by these points from a topmost layer to thenode of a predetermined layer; and displaying the result obtained byordering all or part of the nodes in the predetermined layer, by usingthe points that have been calculated for each node in the predeterminedlayer.
 16. The search system according to claim 15, wherein among thenodes forming the multilayer structure in which the forward networkstructure information maintenance section maintains the forward networkstructure information, (i) a connection is formed from each of the atleast one or more nodes included in any one of the plurality of layersexcept the bottommost layer, toward at least one or more nodes includedin one or more layers at a lower position than the one layer, and eachof the one or more nodes in the one layer is connected to neither thenodes in the one layer nor nodes in the higher layers, or (ii) aconnection is formed from each of the at least one or more nodesincluded in any one of the plurality of layers except the topmost layer,toward at least one or more nodes included in one or more layers at ahigher position than the one layer, and each of the one or more nodes inthe one layer is connected to neither the nodes in the one layer nornodes in the lower layers.